Footnote zone detection in a fixed format document using number of paragraphs in footnote description

Patent metadata

Field	Value
Publication number	US-9703759-B2
Application number	US-201313745127-A
Country	US
Kind code	B2
Filing date	Jan 18, 2013
Priority date	Jan 18, 2013
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

Footnote detection is provided. When converting a fixed format document to a flow format document, footnotes, which may include a footnote description and a footnote reference mark, may be detected and linked with a corresponding footnote reference mark in a main document flow on a page. Additionally, a footnote numbering scheme may be determined and applied to detected footnotes. By providing footnote detection when converting a fixed format document to a flow format document, footnotes may be statically positioned at the end of a page containing the corresponding footnote reference mark.

First claim

We claim:

1. A method for detecting one or more footnotes in a fixed format document, the method comprising:
detecting a footnote zone on a page in the fixed format document including detecting whether the fixed format document includes a footnote separator line;
detecting one or more paragraphs in the footnote zone as footnote candidates, including discarding paragraphs above a selected portion of the fixed format document from being considered as footnote candidates;
determining which of the one or more paragraphs belong to a footnote description of a footnote, including:
determining a number of paragraphs in the footnote description; and
if the footnote description comprises more than a selected number of paragraphs, discarding the footnote candidates in the footnote zone; and
if the footnote description comprises less than the selected number of paragraphs:
detecting a corresponding footnote reference mark in a main document flow on the page for each footnote;
determining a footnote numbering scheme;
applying the footnote numbering scheme to each footnote; and
linking each footnote with the corresponding footnote reference mark in the main document flow on the page.

2. The method of claim 1 , wherein detecting the footnote zone on the page comprises detecting an area at the bottom of a region and including the area at the bottom of the region to the footnote zone.

3. The method of claim 1 , wherein detecting the footnote zone on the page comprises detecting an area below the footnote separator line to the footnote zone.

4. The method of claim 3 , wherein detecting the footnote separator line comprises detecting a line node and determining:
a height of the line node is less than an average text height of text on the page.

5. The method of claim 1 , wherein determining which of the one or more paragraphs belong to the footnote description of a footnote comprises:
analyzing each of the one or more paragraphs starting with last paragraph in the footnote zone;
if the footnote separator line is not found and if the paragraph starts with a superscript number, determining the paragraph is a first paragraph of the footnote description of a footnote; and
if the footnote separator line is found and if the paragraph starts with a number or any text written in superscript, determining the paragraph is the first paragraph of the footnote description of a footnote.

6. The method of claim 5 , wherein paragraphs above the footnote separator line are discarded as possible footnote candidates.

7. The method of claim 1 , wherein detecting the corresponding footnote reference mark in the main document flow on the page for each footnote comprises:
extracting a footnote reference mark from each footnote description; and
analyzing the main document flow on the page for a superscript text run comprising the extracted footnote reference mark.

8. The method of claim 7 , further comprising:
for each footnote description, if the extracted footnote reference mark is not found in the superscript text run, analyzing the main document flow on the page for a non-superscript text run comprising the extracted footnote reference mark.

9. The method of claim 7 , further comprising:
if the corresponding footnote reference mark is found for less than half of the footnotes on the page, discarding the footnotes.

10. The method of claim 1 , where detecting the footnote numbering scheme comprises analyzing each footnote reference mark on all pages of the fixed format document to determine if the footnote reference mark is a valid element in a numbering scheme.

11. The method of claim 10 , further comprising determining the numbering scheme that covers a longest subsequence of footnote reference marks.

12. The method of claim 10 , further comprising:
if the footnote reference mark does not fit into the determined numbering scheme, determining the footnote reference mark to be a custom footnote reference mark to be reconstructed literally.

13. The method of claim 10 , wherein determining the footnote numbering scheme further comprises analyzing whether the footnote reference mark is the valid element of the footnote numbering scheme.

14. The method of claim 1 , further comprising statically positioning each of the one or more footnotes at an end of the page containing the corresponding footnote reference mark.

15. The method of claim 1 , wherein discarding paragraphs above the selected portion of the fixed format document from being considered as footnote candidates further comprises discarding paragraphs above a bottom third of the fixed format document.

16. A system for detecting one or more footnotes in a document, the system comprising:
one or more processors; and
a memory coupled to the one or more processors, the one or more processors operable to:
detect a footnote zone on a page in the document including detecting whether the document includes a footnote separator line;
detect one or more paragraphs in the footnote zone as footnote candidates, including discarding paragraphs above a selected portion of the document from being considered as footnote candidates;
determine which of the one or more paragraphs belong to a footnote description of a footnote, including:
determining a number of paragraphs in the footnote description; and
if the footnote description comprises more than a selected number of paragraphs, discarding the footnote candidates in the footnote zone; and
if the footnote description comprises less than the selected number of paragraphs:
detect a corresponding footnote reference mark in a main document flow on the page for each footnote;
determine a footnote numbering scheme;
apply the footnote numbering scheme to each footnote; and
link each footnote with the corresponding footnote reference mark in the main document flow on the page.

17. The system of claim 16 , wherein the footnote zone comprises an area at the bottom of a region and an area below the footnote separator line.

18. The system of claim 16 , wherein the one or more processors are further operable to:
analyze each of the one or more paragraphs starting with last paragraph in the footnote zone;
if the footnote separator line is not found and if the paragraph starts with a superscript number, determine the paragraph is a first paragraph of the footnote description of a footnote; and
if the footnote separator line is found and if the paragraph starts with a number or any text written in superscript, determine the paragraph is the first paragraph of the footnote description of a footnote.

19. The system of claim 16 , wherein the one or more processors are further operable to:
extract a footnote reference mark from each footnote description;
analyze the main document flow on the page for a superscript text run comprising the extracted footnote reference mark; and
if the extracted footnote reference mark is not found in the superscript text run, analyze the main document flow on the page for a non-superscript text run comprising the extracted footnote reference mark.

20. A computer readable storage device containing computer executable instructions which, when executed by a computer, perform a method for detecting one or more footnotes in a document, the method comprising:
detecting a footnote zone on a page in the document including detecting whether the document includes a footnote separator line;
detecting one or more paragraphs in the footnote zone as footnote candidates, including discarding paragraphs above a

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Zaric Drazen
• Raskovic Milos

Classifications

• G06F40/103

  Formatting, i.e. changing of presentation of documents (automatic justification G06F40/189; automatic line break hyphenation G06F40/191) · CPC title

• G06F16/382

  using citations (hypermedia G06F16/94) · CPC title

• G06F40/134 Primary

  Hyperlinking · CPC title

• G06F40/169

  Annotation, e.g. comment data or footnotes · CPC title

• G06F40/106

  Display of layout of documents; Previewing · CPC title